This invention relates generally to an apparatus and a method for manufacturing plastic and plastic articles and more particularly to a method and apparatus employing a continuously rotating wheel or turret having molding cavities formed on the periphery thereof with cores entering said cavities from various side angles and also radially from within the wheel to produce a continuous web or chain of plastic products connected together by connecting plastic links.
The various means for manufacturing a plastic product by molding can be divided into three main catagories. The first catagory is the use of a plurality of cavities which are placed together in a frame. Plastic is then injected into the cavities from one or more angles in the presence of cores which also can be inserted into the cavities from one or more directions. The plastic is then permitted to cool, the cores withdrawn and the mold disassembled so that the plastic products can be removed. The second means for manufacturing plastic products is to provide a chain or track having thereon a plurality of cores and cavities making up a plurality of molds. The track or chain is moved a predetermined distance to place a certain number of the molds under a plastic extruding source. The core or pins are then inserted into each of the cavities and the plastic is subsequently extruded into said plurality of cavities and the cores removed after cooling. The track or chain is then moved a discrete distance to place another plurality of molds and cavities underneath the plastic extruding source and the process is repeated. By this second approach the resulting plastic product can be formed either separately, in that they are each individual or separated from the other, or they can be linked together on a common carrier or by connecting links between adjacent products.
The third catagory comprises a wheel or turret upon the perimeter of which there are formed a plurality of cavities. A plastic extruding source is placed adjacent the perimeter of the wheel, and as the wheel is rotated past the extruding source or head, plastic is forced into the cavities. The wheel continues to rotate while cooling is effected. The finished product is then removed from the perimeter of the wheel before that portion of the perimeter rotates around and under the extruding head again for the next injection of plastic. Each of the formed plastic products can be connected together on a common carrier strip or by interconnecting links between adjacent products. A variation of the rotating wheel or turret is to cause a wheel to rotate to a given angular distance and then stop. While in a stopped condition plastic is inserted into a given number of the cavities underneath the extrusion head or source. The wheel is then caused to rotate another given angular distance to place a new set of empty cavities under the extruding source or head which are then in turn filled with plastic. The finished product is then removed from the wheel in a continuous strip connected by a common carrier or interconnecting links as mentioned above.
In all known prior art involving a rotating wheel or turret the plastic is forced directly into the cavities as the perimeter of the wheel passes under the extruding head. The plastic product takes the shape of the cavities which have been formed in the perimeter of the wheel or turret. The complexity of the plastic product which can be formed in this manner is limited.